The mother of a 22-month-old Georgia boy who died after being left by his father in a sweltering SUV told police she had researched how children die in hot vehicles, according to search warrants released on Sunday.

The statements by Leanna Harris during police questioning echoed similar comments by her husband, Justin Harris, who has been charged with felony murder and second-degree child cruelty in the death of their son in an Atlanta suburb on June 18.

Justin Harris told police he had recently conducted Internet research about the temperature at which a child could die in a car because he was worried it could happen, a search warrant released on Saturday said.

Leanna Harris has not been charged in the toddler’s death, and the search warrants did not specify when she had done the research.

A medical examiner found that Cooper Harris died of heat stroke, or hyperthermia, after being left strapped in his rear-facing car seat for about seven hours by Justin Harris, who told police he forgot to drop the child off at day care before going to work.

The temperature in the Atlanta area was in the 90s for most of that day, police said.

Witnesses described a distraught Harris pulling into a shopping center parking lot on his way home from work and appearing to frantically try to revive his son. His arrest within hours of the child’s death stirred debate over whether the case was an accident or a crime.

Documents released on Sunday showed police investigators have seized various electronic devices from Justin Harris’ 2011 Hyundai Tucson and the family’s home in Marietta.

At Cooper Harris’ funeral in Alabama on Saturday, Leanna Harris described her husband as a wonderful father, the Atlanta Journal-Constitution reported. Justin Harris remains in jail but spoke to mourners by phone during the service.